Charles-Hubert Gervais (1671–1744), highly regarded in his time, was the only composer of the ancien régime who worked as intendant of music for Philippe II of Orléans and as sous-maître de la musique for Louis XV's Chapelle Royale. In spite of these distinguished positions, his life and works have scarcely attracted the interest of scholars. By bringing into focus Gervais's setting of Psalm 136, new light is shed on the musical activity at Louis XV's court. With Gervais's Super flumina Babilonis available for the first time, scholars can compare it with de Lalande's motet based on the same psalm. Such a comparison will prove that Gervais was a competent and original successor to de Lalande, a conclusion which may explain why Gervais's motet was sung at the Chapelle as late as 1792.